Added cgroup-awareness to Chromium (second draft)

base/process/process_metrics_linux.cc

Index: base/process/process_metrics_linux.cc
diff --git a/base/process/process_metrics_linux.cc b/base/process/process_metrics_linux.cc
index 5d542cc67527dad91035dcfc076e4f28b22ba25f..afc650802228833ee11edfc011b25c02db1ecb29 100644
--- a/base/process/process_metrics_linux.cc
+++ b/base/process/process_metrics_linux.cc
@@ -702,6 +702,60 @@ bool ParseProcVmstat(const std::string& vmstat_data,
 
   return true;
 }
+const std::string GetCgroupMemoryPathString() {
+  std::string cgroup_memory_path = "";
+  std::string mount_info;
+  FilePath mount_file("/proc/mounts");
+  if (!ReadFileToString(mount_file, &mount_info)) {
+    DLOG(WARNING) << "Failed to open " << mount_file.value();
+    return "";
+  }
+  else{
+  for (const StringPiece& line : SplitStringPiece(
+           mount_info, "\n", KEEP_WHITESPACE, SPLIT_WANT_NONEMPTY)) {
+    std::vector<StringPiece> tokens = SplitStringPiece(
+        line, kWhitespaceASCII, TRIM_WHITESPACE, SPLIT_WANT_NONEMPTY);
+    if (tokens.size() <= 1) {
+      DLOG(WARNING) << "mount: tokens: " << tokens.size()
+                    << " malformed line: " << line.as_string();
+      continue;
+    }
+    if (tokens[0] == "cgroup"){
+       if(tokens[3].find("memory") != std::string::npos) {
+          cgroup_memory_path = tokens[1].data();
+      }
+    }
+  }
+  }
+  return cgroup_memory_path;
+}
+
+long IfOnCgroup(std::string cgroup_memory_path_string){
+  bool on_cgroup = false;
+  std::string cgroup_limits_in_bytes = "";
+  // First, cheking if we're on a cgroup
+  if (cgroup_memory_path_string == ""){
+    on_cgroup = false;}
+  else{
+    FilePath cgroup_memory_file((cgroup_memory_path_string+"memory.limit_in_bytes").c_str());
+    std::string cgroup_memory_file_info;
+    if (!ReadFileToString(cgroup_memory_file, &cgroup_memory_file_info)) {
+      on_cgroup =false;}
+    else{
+      cgroup_limits_in_bytes = cgroup_memory_file_info;
+      //file.close();
+      // TODO: is 9223372036854771712 a const?
+      if (cgroup_limits_in_bytes != "9223372036854771712"){
+        on_cgroup = true;}
+      else{
+        on_cgroup = false;}
+    }
+  }
+  if (!on_cgroup){
+    return 0;}
+  else{
+  return (atol(cgroup_limits_in_bytes.c_str()) / 1024);}
+}
 
 bool GetSystemMemoryInfo(SystemMemoryInfoKB* meminfo) {
   // Synchronously reading files in /proc and /sys are safe.
@@ -719,7 +773,14 @@ bool GetSystemMemoryInfo(SystemMemoryInfoKB* meminfo) {
     DLOG(WARNING) << "Failed to parse " << meminfo_file.value();
     return false;
   }
-
+  else{
+   std::string cgroup_memory_path_string = GetCgroupMemoryPathString();
+   long total_memory_kb = IfOnCgroup(cgroup_memory_path_string);
+    if (total_memory_kb > 0)
+    {
+      meminfo->total =  total_memory_kb;
+    }
+  }
 #if defined(OS_CHROMEOS)
   // Report on Chrome OS GEM object graphics memory. /run/debugfs_gpu is a
   // bind mount into /sys/kernel/debug and synchronously reading the in-memory